1. Technical Field
The present invention relates to an image scanning apparatus and a method of controlling the same.
2. Related Art
Image scanning apparatuses that include a reflective document lamp and scan reflective documents, such as documents and photographs, have been proposed. In many cases, a cold cathode fluorescent lamp (hereinafter, referred to as a CCFL) is used as the reflective document lamp. However, when the CCFL is left for a long time in a dark environment in which light is shielded, the number of initial electrons contributing to discharge required for the lighting of the CCFL in a lamp tube is reduced. As a result, the starting time from the application of a voltage to the lighting of the lamp is lengthened, that is, ‘a starting performance in a dark environment’ is lowered.
In order to solve the above-mentioned problem, JP-A-1-130462 discloses a method of using an auxiliary light source. In the method disclosed in JP-A-1-130462, an auxiliary light source, such as a candescent lamp or a light emitting diode, is provided, and light from the auxiliary lamp is emitted to a discharge lamp when the discharge lamp starts to increase the number of initial electrons of the lamp, thereby shortening the starting time of the lamp.
However, in the method of using the auxiliary light source, it is necessary to provide an additional auxiliary light source for illuminating the discharge lamp, which results in an increase in the manufacturing costs of the apparatus.